Swimming Pool Water Chemistry For The Pool Guy (Part 4) Total Dissolved Solids (TDS)
Total Dissolved Solids
What are total dissolved solids? This article is all about TDS so if you are new to this term then stay tuned. There are 0 TDS in a glass of distilled water, while we may find 500ppm TDS in a regular drinking water, but what about our pool?
Total Dissolved Solids:
Fundamentally a total dissolved solids is the extent of everything which has been ever disbanded in our pool. It could include minerals like calcium, phosphate, and sodium, algae, remains, dust particles or swimmer waste.
Here is the key thing about Total Dissolved Solids in swimming pools and I will repeat it a couple of times in this article.
Not all TDS are bad. It depends on what the total dissolved solids are composed of, but the swimming pool industry, pool guys, and pool stores don’t have sophisticated testing methods that can tell us the breakdown of the TDS.
How does it pertain to us pool guys? When you have water evaporation, what evaporates is pure water, and it leaves behind everything else, all the chemicals, phosphates, sodium, etc. in the pool. So, all of that is still in the pool. As times goes by you will have less pure water and more total dissolved solids in the water. Then when you add a chemical to the pool instead of the chemical doing the job that you want it to do it starts fighting with some of those total dissolved solids in the pool and the chemical can’t do its job.
You might add chlorine to the pool, but because your TDS are high then it can’t do its job. Or you might add algicide, but it doesn’t work because instead of killing the algae it is fighting with the total dissolved solids that are in the water.
Think of it this way. If your pool has high TDS in the water and you take out all the pure water the TDS would be all the mud or gunk that is left in the bottom of the pool. If you don’t take out the TDS and refill the pool with water, you are filling the pool with all that mud and gunk at the bottom of the pool and the rest with water.
As pool guys, we know that we always want pure water in our pools. It makes the process of keeping the pool balanced and easy to service.
Some pool guys will say that they have high levels of TDS in their swimming pool and everything is great. But it will all depend on what the TDS is composed of. Are TDS always bad? No, but the industry does not have the sophisticated tools for the pool guys or pool stores to tell us what the TDS are composed of. If you are having issues with your pool and keeping it balanced it’s something you need to consider.
Is it a problem with a high TDS level?
Here the question, is it safe to have a high level of TDS? It could be safe in some cases, but in some cases, it is not. Mainly the problem with TDS is linked to the type of TDS in water. So, if the level of sulfates and chlorides are increasing, then it could be an alarming sign. Contained in high levels of TDS you will normally find high levels of phosphates and nitrates, which will eat up more of your chlorine and provide nutrients to algae.
Remember that not all TDS are bad, it’s based on what the TDS are composed of. For example, a pool with a salt system will give you a high TDS because of the salt levels. Having salt in your pool for your salt system will be required. So, you want to test the TDS levels and keep an eye out for certain signs.
- The increased level of TDS could reduce the efficiency of chlorine in the water, give water a slightly dull appearance and promotes the growth of algae.
- High level of TDS could cause the corrosion of metal elements in the pool, including pipes, ladder and pool lights because of an increase in the conductive power of water.
- High level of TDS could corrupt the results of various tests including a test for chlorine.
- Having high TDS will affect your pocket and profits. Because it will reduce the efficiency of chemicals in the water you will need to add more chemicals to the pool to get the job done. The more chemicals you add the more it will cost you to keep up the pool.
How to reduce the level of TDS in pool water?
If you are sensing that your pool water is exhibiting problems of TDS, you will want to confirm it. Here are a couple of things that can be happening that might be a sign of high TDS:
- A dull and cloudy water despite proper filtration and circulation or water.
- Having trouble in maintaining the level of chlorine in water to the desired period in spite of the use of cyanuric acid.
- Having a problem with algae formation even though the phosphate level in the water is in line.
- The water feels salty with the accumulation of salt deposits.
If you are having problems as mentioned above, then there is a probability your TDS might be high in your pool. Let’s just dive into the solutions to reduce the level of TDS in water.
Reduction of TDS in the pool:
Just like cyanuric acid, we have no option in case of TDS as well. There are no chemicals available in the market which can reduce the level of TDS in pool water. There is only one solution to this problem-dilution of water.
All you have to do is to take out some of the water and replace it with fresh water. In some cases, you might want to replace all the water. However, always keep in mind that you must check for all the other possible reasons before going for dilution of water.